EP1753649B1

EP1753649B1 - Automatic central buffer coupling for rail vehicles

Info

Publication number: EP1753649B1
Application number: EP05735101A
Authority: EP
Inventors: Soonhee Kang; Helmut Poiss; Christian BÖCHZELT; Josef Poisinger
Original assignee: Bombardier Transportation GmbH
Current assignee: Alstom Transportation Germany GmbH
Priority date: 2004-06-08
Filing date: 2005-04-20
Publication date: 2008-09-03
Anticipated expiration: 2025-04-20
Also published as: ATE407047T1; PL1753649T3; GB2414975A; EP1753649A1; PT1753649E; ES2313327T3; WO2005120921A1; DE602005009524D1; HRP20080511T3

Abstract

An automatic central buffer coupling for rail vehicles has a coupling head (1) with a projection (25), a hook (3) mounted on a fixed pivot bearing (4) in the coupling head for swinging in a coupling position, an articulated arm mechanism (10, 11, 12, 13, 14) mounted in the coupling head and spring means (17, 19; 18, 20) acting on the hook (3). The articulated arm mechanism comprises a first articulated arm (10) which is pivotally connected to a second pivot bearing (12) defining a fixed axis of rotation with respect to the coupling head, wherein the hook (3) is connected by means of a pivot joint (13) to a second articulated arm (11) which is connected by means of a second pivot joint (14) to the first articulated arm (10) whose movement is limited by a wall (28) or stop provided with the coupling head. In the coupling position of the hook (3) the axes of rotation defined by the first and second pivot joints (13, 14) and the second pivot bearing (12) are intersecting an arc-shaped line (30) and the articulated arm mechanism is pressed by means of a spring means (17, 19) against the stop or wall (28) of the coupling head, wherein the spring means is supported on a supporting bearing (21) located on the concave side of the arc-shaped line (30).

Description

FIELD OF THE INVENTION

This invention relates to an automatic central buffer coupling for rail vehicles comprising a coupling head with a projection, a hook mounted on a fixed pivot bearing in the coupling head for swinging in a coupling position, an articulated arm mechanism mounted in the coupling head and spring means acting on the hook.

BACKGROUND OF THE INVENTION

It is well known that particularly modern light rail passenger transit vehicles, such as streetcars, subway cars, and the like, are capable of being independently operated as a single passenger transit vehicle. Such rail vehicles are often operated as a single vehicle, particularly, during times when passenger travel is at a low volume. On the other hand, during times of high volume passenger travel, such as the morning and evening "rush hours", such passenger transit vehicles are operated as units of two or more vehicles. In order to permit the operation of such multiple car units, such transit vehicles are provided with coupling means at their forward and rearward ends for selectively coupling and uncoupling the transit vehicles together according to the respective needs.
In order to permit a quick and convenient coupling and uncoupling of rail vehicles automatic central buffer couplings have been developed.
US 2,161,724 discloses an automatic central buffer coupling consisting of a pair of mating coupling heads each having a rotatable hook plate and a coupling eye pivoted to the hook plate. Pivotally connected to each hook plate is a bow-shaped lever arm which is designed to engage with the coupling eye of the other hook plate. Moreover, each hook plate is provided with a coupling spring which tends to rotate the hook plate in a coupling position. The lever arms and the hook plates form a parallelogram. When unlocking this known central buffer coupling the hook plates are rotated against the force of the coupling springs until the bow-shaped lever arms can be disengaged from the coupling eyes.
GB 1,247,128 discloses a central buffer coupling for rail vehicles comprising a locking pin for locking the coupling with a counter coupling in a coupled position, a manually operable lever for releasing the locking pin and hydraulic or pneumatic piston cylinder means adapted to alternatively actuate the manually operable lever to release the coupling.
US 3,405,811 discloses an automatic hook type coupler for rail vehicles having pivotally mounted in its coupling head an unlocking cam and a lock. The unlocking cam in an uncoupling operation acts on said hook and a corresponding hook of a mating coupler engaged thereby for swinging said hooks to uncoupling position. The lock on coupling of said couplers locks the hook of the mating coupler in coupling position. Each coupling head is provided with an uncoupling lever which can be manually or automatically actuated for swinging both hooks to uncoupling position through the unlocking cam while releasing the hook of the mating coupler from the lock. An operative connection is provided between the levers when the couplers are coupled for enabling actuation of one to actuate both in unison. The operative connection permits the swing of the hooks to be so restricted that the couplers cannot be uncoupled unless both hooks are swung to uncoupling position.
A further example of an automatic central buffer coupling for rail vehicles is disclosed in BE-A-382 532 .

SUMMARY OF THE INVENTION

The object of the present invention is to provide another automatic central buffer coupling of the type mentioned in the introduction which permits simple coupling and uncoupling at a high level of functional reliability.
According to the invention, an automatic central buffer coupling for rail vehicles is provided having a coupling head with a projection, a hook mounted on a fixed pivot bearing in the coupling head for swinging in a coupling position, an articulated arm mechanism mounted in the coupling head and spring means acting on the hook. The articulated arm mechanism comprises a first articulated arm which is pivotally connected to a second pivot bearing defining a fixed axis of rotation with respect to the coupling head, wherein the hook is connected by means of a pivot joint to a second articulated arm which is connected by means of a second pivot joint to the first articulated arm whose movement is limited by a wall or stop provided with the coupling head. In the coupling position of the hook the axes of rotation defined by the first and second pivot joints and the second pivot bearing are intersecting an arc-shaped line and the articulated arm mechanism being pressed by means of a spring means against the stop or wall of the coupling head, wherein the spring means is supported on a supporting bearing located on the concave side of the arc-shaped line.
The central buffer coupling according to the invention distinguishes in that it permits a simple and reliable coupling and uncoupling.
In a preferred embodiment of the central buffer coupling according to the invention a third articulated arm is connected by means of a third pivot joint to the hook. The third articulated arm projects from the hook in its uncoupling position towards an opening in the front of coupling head for co-operating with a projection of a mating coupling head of another rail vehicle in order to trigger a movement of the hook from the uncoupling position in the coupling position. A second spring means acts on the third articulated arm and being supported on a second supporting bearing located on the second articulated arm of the articulated arm mechanism.
Further preferred and advantageous embodiments of the central buffer coupling according to the invention are given in the subclaims forming a part of this disclosure. For a better understanding of the invention, its operating advantages and specific objects attained by its uses, reference is made to the accompanying drawings and descriptive matter in which a preferred embodiment of the invention is illustrated.

BRIEF DESCRIPTION OF THE DRAWINGS

One exemplary embodiment of the present invention is shown in the drawing, and will be explained in greater detail below. The figures of the drawing show simplified schematic representations, which are not true to scale. In the drawings:

Fig. 1: is a perspective oblique view of a coupling head having a hook pivotally mounted therein and a projection, with the housing of the coupling head shown partly cut away and the front surface located in the forward direction, and with a hook of a mating coupling head (not shown) of another rail vehicle;
Fig. 2: is a horizontal sectional view of the coupling head according to Fig. 1, wherein a projection of a mating coupling head (not shown) is pushed against an articulated arm or tappet pivotally connected to the hook of the coupling head;
Fig. 3: is a horizontal sectional view of the coupling head according to Fig. 1 in the coupled position, wherein the projection of a mating coupling head (not shown) is completely in an opening of the coupling head and the two hooks are engaged in their coupled position; and
Fig. 4: is a horizontal sectional view of the coupling head according to Fig. 1 with one hook being in its uncoupled position.

DETAIL DESCRIPTION OF THE PREFERRED EMBODIMENT

As is shown in Fig. 1, a coupling head 1 comprises a coupling housing 2 in which a hook 3 is pivotally mounted on a pivot bearing 4 defining a fixed axis with respect to the coupling housing. The hook 3 has a forked section with upper and lower fork legs 5, 6 disposed at the opposite end of the head section 7 of the hook 3. The pivot bearing or pivot pin 4 is positioned between the forked section and the head section 7. The head section 7 projects into a projection 25 of the coupling head 1 through an opening 8 beyond the front surface or front plate 9 of the coupling housing 2.
Furthermore, the hook 3 is provided with an articulated arm mechanism comprising a first articulated arm 10 and a second articulated arm 11. The first articulated arm 10 is pivotally connected to a second pivot bearing or pivot pin 12 defining another fixed axis of rotation with respect to the housing of coupling head 1. The first articulated arm 10 has also a forked section, wherein the second articulated arm 11 is accommodated between the fork legs 5, 6 of the hook 3 and the fork legs of the first articulated arm 10. The hook 3 is connected by means of a pivot joint 13 to the second articulated arm 11 which is connected by means of a second pivot joint 14 to the first articulated arm 10.
Furthermore, a third articulated arm 15 is provided which serves as a tappet and being connected by means of a third pivot joint 16 to the hook 3. The third articulated arm or tappet 15 is arranged between the fork legs 5, 6 of the hook 3 with the third pivot joint 16 being located between the fixed pivot pin 4 and the pivot joint 13.
The articulated arms 10, 11, 15 are provided with two spring means each comprising a helical spring 17, 18 and a guide means 19, 20 for maintaining an essential straight longitudinal extension of the respective helical spring 17, 18 during movement of the articulated arm mechanism. A first or main spring means 17, 19 is supported on a supporting bearing 21 disposed between the pivot bearing or pivot pin 4 of the hook 3 and the pivot bearing or pivot pin 12 of the first articulated arm 10. The other end of the main spring means 17, 19 acts directly or indirectly on the first and second articulated arms 10, 11. The point 22 where the spring force of the main spring means is applied to the articulated arm mechanism lies essentially in the area of the pivot joint 14.
The second spring means 18, 20 is associated to the second and third articulated arms 11, 15. The second spring means 18, 20 acts on the third articulated arm 15 in a point of application of force 23 lying adjacent the pivot joint 16. The other end of the second spring means 18, 20 is supported on a supporting bearing or point of application of force 24 located on the second articulated arm 11 adjacent to the pivot joint 13. The first 24 and second 23 pivot pins are formed by pivot joints. The second spring means 18, 20 is accommodated between fork legs of the second and third articulated arms 11, 15.
For co-operating with a projection 25' of a mating coupling head (not shown) of another rail vehicle the third articulated arm 15 projects from the hook 3 in its uncoupling position towards the opening 8 in the front 9 of coupling head 1.
The movement of the hook 3 from its uncoupled position in its coupled position is caused by the pressure action of the projection 25' of a mating coupling head applied on the third articulated arm or tappet 15. In Figures 1 and 2 the situation is shown in which the third articulated arm 15 is in a ready position with respect to the projection 25' of the counter coupling head (not shown). By pushing the third articulated arm or tappet 15 towards the rear wall 26 of the coupling housing 2 the hook 3 is pivoted so that its head section 7 approaches its coupled position. During the rotation of the hook 3 from the uncoupled position shown in Fig. 2 to the coupled position shown in Fig. 3 the pressure spring 17 of the main spring means reaches its shortest length, whereby when rotating the hook 3 further the main spring means is able to move the common pivot joint 14 and thus the first and second articulated arms 10, 11 towards a wall of the coupling housing 2.
As is shown in Fig. 3, the movement of the first articulated arm 10 is limited by a stop 27 provided with the coupling head (cf. Fig. 4). The stop 27 may consist of a wall 28 of the coupling housing 2. In the present embodiment the wall section 28 presenting the stop is oblique with respect to the rear wall 26 and the front surface 9 of the coupling housing 2. Accordingly, the movement of the pivot joint 14 and the articulated arm mechanism is limited by the stop 27 or housing wall section 28. The articulated arm mechanism is pressed by means of the main spring means 17, 19 against the stop 27 or wall 28 of the coupling head 1. When the articulated arm mechanism reaches the stop 27 or wall section 28 of the coupling housing 2 the hook 3 engages a coupling section 29 of the hook 3' of a mating coupling head of another rail vehicle (cf. Fig. 3).
When the hook 3 is moved in its coupled position the first and second articulated arms 10, 11 are moved beyond the position in which their longitudinal axes coincide with the straight line connecting the axes of rotation of the pivot point 13 and the fixed pivot pin 12. In the coupled position of the hook 3 the longitudinal axes of the first and second articulated arms 10, 11 form an obtuse angle. Accordingly, in the coupled position of the hook 3 the axes of rotation defined by the first and second pivot joints 13, 14 and the second pivot bearing 12 intersect an arc-shaped line indicated in Fig. 3 by the dashed line 30. The supporting or pivot point 21 of the main spring means 17, 19 is located on the concave side of the arc-shaped line 30.
When the pivot joint 14 of the articulated arm mechanism is pressed by means of the main spring means 17, 19 against the stop 27 or wall 28 of the coupling head 1, the hook 3 remains locked even if a pull force is applied on the hook section associated to the section 29 of the hook 3' of the mating coupling head.
Associated to the third articulated arm or tappet 15 is a stop 31 projecting from the rear wall 26 of the coupling housing 2. The stop 31 has an oblique front co-operating with an sharp-shaped end of the third articulated arm 15. After the front of the projection 25' of the mating coupling head has reached its deepest position in the opening 8 and before the pivot joint 14 is pressed against the stop 27 or oblique wall section 28 of the coupling housing 2 the third articulated arm 15 touches with its sharp-shaped end the stop 31 whereby the third articulated arm 15 is swung such that its opposite end is moved towards the fixed pivot bearing or pivot pin 4 in order not to get stuck with the projection 25' of the mating coupling head of another rail vehicle during uncoupling of the hook 3.
The third articulated arm 15 comprises a stop 32 which co-operates with the front edge of the upper leg 5 of the hook 3. By means of the stop 32 two stop positions for the swing movement of the third articulated arm 15 are defined with respect to the hook 3.
During the swing movement of the third articulated arm 15 from its position shown in Fig. 2 into the position shown in Fig. 3 the helical spring 18 of the second spring means is pressed to a shortest length wherein the helical spring 18 has a longer longitudinal extension in the respective positions shown in Figures 2 and 3. Due to the spring force of the pressure spring 18 the third articulated arm 15 retains in the coupling position of the hook 3 in a position in which it is spaced with respect to the projection 25' of the counter coupling head (cf. Fig. 3).
In order to uncouple the two hooks 3, 3' the first articulated arm 10 is rotated around its fixed axis 12 away from the wall 28 of the housing 2. The rotation of the first articulated arm 10 can be performed by a manually operable lever (not shown) and/or electric, hydraulic or pneumatic piston cylinder means (not shown). Due to its pivot connection with the first articulated arm 10 the hook 3 is rotated around its fixed pivot bearing or pivot pin 4. Just after the pressure spring 17 has been moved beyond the position in which its longitudinal extension has the shortest length, the main spring means 17, 19 will automatically swing the hook 3 further into the uncoupling position (cf. Fig. 4).
Each of the projections 25, 25' of the respective coupling head has a recess 33, 33' for allowing the hook 3, 3' t swing from its uncoupled position in its coupled position and vice versa. While the hook 3 is moved in its uncoupled position the second articulated arm 11 is rotated too and the helical spring 18 is moved beyond the position in which its longitudinal extension has the shortest length (cf. Fig. 4). Due to the spring force present in this position the third articulated arm or tappet 15 will swing back to the ready position shown in Fig. 2 as soon as the vehicle having the mating coupling head with the projection 25' is driven away.
The projection 25' of the mating coupling head is designed with respect to the third articulated arm 15 such that during the coupling process the third articulated arm 15 with the stop 31 can trigger the movement of the hook 3 from the uncoupled position and the third articulated arm 15 cannot move back towards the fixed pivot bearing or pivot pin 4.
While a specific embodiment of the invention has been shown and described in detail to illustrate the application of the automatic central buffer coupling according to the invention, it will be understood that the invention may be embodied otherwise without departing from the invention as defined in the accompanying claims.

Claims

An automatic central buffer coupling for rail vehicles comprising a coupling head (1) with a projection (25), a hook (3) mounted on a fixed pivot bearing (4) in the coupling head for swinging in a coupling position, an articulated arm mechanism (10, 11, 12, 13, 14) mounted in the coupling head and spring means (17, 19; 18, 20) acting on the hook, wherein the articulated arm mechanism comprises a first articulated arm (10) which is pivotally connected to a second pivot bearing (12) defining a fixed axis of rotation with respect to the coupling head, characterised in that the hook (3) is connected by means of a pivot joint (13) to a second articulated arm (11) which is connected by means of a second pivot joint (14) to the first articulated arm (10) whose movement is limited by a wall (28) or stop (27) provided with the coupling head, wherein in the coupled position of the hook (3) the axes of rotation defined by the first and second pivot joints (13, 14) and the second pivot bearing (12) are intersecting an arc-shaped line (30) and the articulated arm mechanism is pressed by means of a spring means (17, 19) against the stop (27) or wall (28) of the coupling head, and wherein the spring means (17, 19) is supported on a supporting bearing (21) located on the concave side of the arc-shaped line (30).
A central buffer coupling according to Claim 1, characterised in that a third articulated arm (15) is connected by means of a third pivot joint (16) to the hook (3), the third articulated a (15) projecting from the hook (3) in its uncoupled position towards an opening (8) in the front (9) of coupling head for co-operating with a projection (25') of a mating coupling head of another rail vehicle in order to trigger a movement of the hook (3) from the uncoupled position in the coupled position.
A central buffer coupling according to Claim 2, characterised in that a second spring means (18, 20) which is supported on a first pivot pin (24) located on the second articulated arm (11) of the articulated arm mechanism acts on the third articulated arm (15) for allowing the third articulated arm (15) to swing around the third pivot joint (16) in order to avoid that the third articulated arm (15) will get stuck with a projection (25') of a mating coupling head of another rail vehicle during uncoupling of the hook (3) on the one hand, and on the other hand in order to swing the third articulated arm (15) in a ready position for a next coupling operation as soon as the projection (25') of a mating coupling head of another rail vehicle is drawn away.
A central buffer coupling according to Claim 2 or 3, characterised in that the third articulated arm (15) comprises a stop (32) defining stop positions of the third articulated arm (15) with respect to the hook (3).
A central buffer coupling according to any of the preceding Claims 2 to 4, characterised in that the projection (25') of the mating coupling head is designed with respect to the third articulated arm (15) such that during coupling operation the third articulated arm (15) can trigger the movement of the hook (3) from the uncoupled position in the coupled position and the third articulated arm (15) cannot move back towards the fixed pivot bearing (4) of the hook (3).
A central buffer coupling according to any of the preceding Claims 2 to 5, characterised in that the second spring means (18, 20) is pivotally connected by a first pivot pin (24) to the second articulated arm (11) and by a second pivot pin (23) to the third articulated arm (15), wherein the second spring means (18, 20) comprises a helical spring (18) whose longitudinal extension has a shortest length between the coupled and uncoupled positions of the hook (3).
A central buffer coupling according to any of the preceding Claims 2 to 6, characterised in that the projection (25, 25') of the coupling head has a recess (33, 33') for allowing the hook (3, 3') to swing from its uncoupled position in its coupled position and vice versa.
A central buffer coupling according to any of the preceding Claims 2 to 7, characterised in that each of the spring means (17, 19; 18, 20) is provided with a helical spring (17, 18) having its own guide means (19, 20) for maintaining an essential straight longitudinal extension of the helical spring (17, 18) during movement of the articulated arm mechanism.
A central buffer coupling according to any of the preceding Claims 2 to 8, characterised in that the hook (3) comprises a forked section having upper and lower fork legs (5, 6), wherein the fork legs (5, 6) accommodate the second and third articulated arms (11, 15) between them.
A central buffer coupling according to any of the preceding Claims 1 to 9, characterised in that the first articulated arm (10) comprises a forked section having upper and lower fork legs, wherein the fork legs accommodate the second articulated arm (11) between them.
A central buffer coupling according to any of the preceding Claims 2 to 10, characterised in that the coupling head (1) comprises a housing (2) with a stop (31) projecting from an inner surface of the housing (2), the stop (31) being associated to the third articulated arm for pivoting the third articulated arm (15) such that it can pass the front of the projection (25') of the mating coupling head by moving the articulated arm mechanism after the front of the projection (25') of the mating coupling head has reached its deepest position in the opening (8) in the front (9) of coupling head and before the hook (3) has reached its coupled position completely.